Fire suppression fire systems are often installed in commercial buildings. Typically, those buildings are subdivided into multiple rooms. Commonly, conventional fire suppression systems are designed either as total flooding systems using an inert gas under pressure or localized streaming fire suppression systems using liquid suppressant under pressure. In total flooding systems, an inert gas is rapidly admitted into a room, commonly through a plurality of nozzles mounted in an array in the ceiling of the room, to fill the volume defined within the room. The inert gas may be nitrogen, carbon dioxide, argon, neon, helium or other chemically non-reactive gas, or mixtures of any two or more of these gases. For example, a mixture of 50% argon and 50% nitrogen is commonly used in inert gas fire suppression system. The inert gas not only removes heat from the fire, but also dilutes the oxygen content within the room to a level low enough that combustion can not be sustained. Typically, conventional inert gas systems are sized to reduce the oxygen content in the atmosphere within the environment of the protected area to a level below 12.5 percent within one minute. Consequently, a large number of high-pressure cylinders of inert gas, typically at a pressure between 200 to 300 bars must be provided to store the necessary volume of inert gas. A large centralized storage area must be dedicated for placement of the required inert gas storage cylinders.
Conventional streaming fire suppression systems spray a mist of liquid suppressant over a localized area beneath the spray cone of a distribution nozzle. Commonly, a number of distribution nozzles are arrayed over the space being protected and are supplied with liquid suppressant, for example water or a liquid chemical agent, from a centralized source. Typically, the liquid suppressant is fed under pressure and conveyed through a network of pipes to the various individual distribution nozzles. Generally, the distribution nozzles are designed to emit a mist of liquid suppressant having a droplet size in the range of between 5 and 60 micrometers. The mist may be produced simply by forcing the liquid suppressant through the openings of the nozzle or through atomization means incorporated in the nozzle.
U.S. Patent Application Publication No. US2005/073131A1 discloses a fire and explosion suppression system wherein high pressure water from a central storage tank is suspended in a flow of nitrogen gas or a mixture of nitrogen and argon gases and distributed to an array of a plurality of distribution nozzles and emitted as a mist of water droplets over a localized area. U.S. Patent Application Publication No. 2006/0278410 discloses a fire and explosion system wherein high pressure water from a central storage tank is passed through a network of pipes to a plurality of high velocity low pressure emitters wherein the water is atomized and discharged into a high pressure inert gas stream passing out of the emitter. U.S. Pat. No. 7,153,446, also published as Patent Application Publication No. US2005/0144949A1, discloses a fire and explosion suppression system wherein a liquid chemical agent fire suppressant under pressure from a central storage tank is suspended in a flow of inert gas and is distributed to an array of a plurality of distribution nozzles and emitted as a mist of liquid droplets over a localized area. A number of exemplary liquid chemical agents suitable for use as fire suppressants are also disclosed in U.S. Pat. No. 7,153,446.
A form of fire suppression system using a commercially available liquid chemical fire suppressant is commonly referred to as a clean agent gaseous fire suppression system because the chemical agent leaves no residue upon evaporation. Clean agent fire suppression systems are often installed in rooms or areas of buildings wherein equipment or goods are housed that could be damaged by water, powder or foam. In a system of this type, a chemical fire suppression agent that is stored in a tank or cylinder as a liquid under pressure is pushed by a gaseous propellant, typically nitrogen, argon or carbon dioxide, from a tank or cylinder of propellant arranged in series flow relationship with the tank or cylinder of chemical agent, through a network of pipes to and through a plurality of distribution nozzles arrayed across the ceiling area or walls of the space being protected. The chemical fire suppression agent is a volatile chemical that exists as a liquid when confined under pressure in a closed vessel, but rapidly vaporizes from its liquid state to a vapor state when sprayed via the distribution nozzles into the ambient atmosphere to form a gaseous mixture with the air within the space being protected which does not support combustion and extinguishes fires. The distribution nozzles function to atomize or otherwise break the liquid chemical fire suppressant into small droplets to facilitate evaporation. An example of a clean agent gaseous fire suppression system is disclosed in each of U.S. Pat. No. 6,763,894 and U.S. Patent Application Publication No. US2005/0001065A1.